Objective To investigate the morphological and immunophenotypic characteristics of phyllodes tumors (PT) and explore their significance in differential diagnosis and evaluation of prognosis.Methods 48 specimens with PT were observed under light microscope with HE and immunohistochemical staining (EnVision method).The antibodies including CD34,CD10,CD117,p53,and Ki-67 were used.10 cases of fibroadenoma were compared and the clinical data and follow-up results were analyzed retrospectively.Results All of 48 cases with PT presented as well-circumscribed masses with typically leaflike structures composed of double-layered epithelial component arranged in clefts and overgrowing hypercellular mesenchymal component.31 benign,12 borderline,and 5 malignant PT were diagnosed based on stromal overgrowth,cellular pleomorphism,mitosis,margins,and others.Focal necrosis was detected in 3 malignant cases and liposarcoma component existed in 1 case.Immunohistochemical staining showed that the positive rates of CD34 were 93.5 ％,58.3 ％,0 in benign,bordline,and malignant PT respectively,there were significant differences between each groups (P ＜ 0.05).The expression of CD10 were 25.8 ％,83.3 ％,80.0 ％,its expression in benign group was significantly different compared with bordline and malignant PT (P ＜ 0.05).p53 was expressed in three groups with no significant difference (P ＞ 0.05).CD117 and Ki-67 had high expression comparatively in malignant PT.All cases were treated surgically with a local recurrence rate of 22.9 ％.Conclusions Reasonable surgery pattern based on accurate histopathological diagnosis is crucial to reduce the local recurrence rate of PT.Immunohistochemistry examination in PT is helpful to the differential diagnosis and evaluation of prognosis.